Contrary to most previous findings, women’s clothing style and grooming did not change according to cycle phase or hormone levels; women may not advertise their fertility with different clothing styles or make-up usage

Probing ovulatory cycle shifts in women’s make-up and clothing style. Julia Stern, Stephanie Rudolph, Lars Penke. Human Behavior and Evolution Society 31st annual meeting. Boston 2019. http://tiny.cc/aa1w6y

The existence of ovulatory cycle shifts in women’s mate preferences and sexual desire has been discussed controversially, highlighting methodological criticism and the need for high powered replication studies. However, there is still a lack of replication studies investigating whether women actually advertise their fertility to signal sexual proceptivity to men, by dressing more attractive (wearing red, sexy or skin revealing clothes) and spending more time and effort in grooming. We addressed this lack of research in a large, pre-registered within-subject study including salivary hormone measures and luteinizing hormone tests. One-hundred-fifty-seven female participants have been photographed in a standardized setting four times across two ovulatory cycles. All photographs were coded on a number of variables for three dimensions: a) clothing color (e.g. wearing red), b) body exposure (e.g. wearing skin revealing clothes), c) grooming (incl. make-up use, hairstyle or accessoires). Multilevel intraindividual comparisons revealed that, contrary to most previous findings, women’s clothing style and grooming did not change according to cycle phase or hormone levels. These results indicate that women may not advertise their fertility with different clothing styles or make-up usage. Hormonal mechanisms and implications for estrus theories will be discussed.

The fact that women wrote more graffiti with sexual content might be explained by the SIDE-model which states that breaking with social norms is easier in groups or in situations of total anonymity

He writes a lot, she gets to the point - sex differences in bathroom graffiti. Kathrin Masuch, Susanne Schmehl, Elisabeth Oberzaucher. Human Behavior and Evolution Society 31st annual meeting. Boston 2019. http://tiny.cc/aa1w6y

Abstract: Graffiti might be seen as a special kind of art or vandalism, but they are a special way of communication. Public bathrooms are most suitable for research on graffiti as they offer privacy and shield from the influence of other persons. Earlier research on graffiti showed that women are not as likely as men to create graffiti. Robin Dunbar claimed that the content of gossip is based on evolutionary strategies. Therefore, females tend to talk about social interactions and support, whereas men are more likely to verbally intimidate possible competitors. We examined 165 bathrooms in restaurants and bars and classified 4747 graffiti. We picked locations of high variability to ensure high social and educational diversity of visitors. Data analysis revealed a number of sex differences. Graffiti conveying social information and sexual content are found more often in ladies’ bathrooms, but generally, more graffiti are found in men’s rooms. The results partially support earlier findings but also raise new questions: The fact that women wrote more graffiti with sexual content might be explained by the SIDE-model which states that breaking with social norms is easier in groups or in situations of total anonymity.

Sense of humor is a sexuality selected trait, signalling underlying mate quality and intelligence; women view humor production ability as more important when choosing a mate; men are better at it

Sex differences in humor production ability - a meta-analysis. Gil Greengross, Paul J. Silvia, Emily C. Nusbaum. Human Behavior and Evolution Society 31st annual meeting. Boston 2019. http://tiny.cc/aa1w6y

Abstract: There is abundant evidence that sense of humor is a sexuality selected trait, signalling underlying mate quality and intelligence. Consistent with sexual selection and mental fitness indicator theories, women view humor production ability as more important when choosing a mate. However, it is not clear if men actually possess higher humor abilities than women. We offer the first comprehensive quantitative meta-analysis on the topic, aimed at measuring the magnitude of such differences, if present. We included studies where participants identified as male or female created humor output that was assessed for funniness by independent raters who were blind to any characteristics of the subjects. Our meta-analysis includes 36 effect sizes from 28 studies (N = 5057, 67% women, including college and non-college students). Twenty of the 36 effect sizes, accounting for 61% of the participants, were not previously published. Results based on random-effects model revealed that men’s humor output was rated as funnier than women’s, with a combined effect size d = 0.321. Results were robust across various moderators and study characteristics, and multiple tests indicated that publication bias is unlikely. Overall, the results are consistent with the signalling hypothesis, and the view that humor is a sexually selected trait.

Male Solosexuality: A man's preference to engage in masturbation as a sole or primary means of sexual expression; the central emotional hallmark is admiration, veneration, and glorification of the penis

The Practice, Identity, and Ideology of Male Solosexuality: Description and Sexual Health Overview. Bill Herring. Sexual Addiction & Compulsivity, Jun 1 2019. https://doi.org/10.1080/10720162.2019.1615586

Abstract: This article introduces the core characteristics of male solosexuality, a recent identity construction, ideological narrative and set of associated sexual practices organized around communal online male masturbation and idealization of the penis. Behaviorally, solosexuality refers to a man's preference to engage in masturbation as a sole or primary means of sexual expression, while its central emotional hallmark is admiration, veneration, and glorification of the penis. After introducing the central behavioral and ideological components of male solosexuality this article applies a concise set of sexual health principles to assess the potential benefits and risks of what some people consider to be not just a collection of sexual attitudes and behaviors but an emerging sexual identity. This article reviews a range of potential motivations for solosexual behavior and shows how the same behavior may represent different degrees of adaptive or problematic components among its practitioners.

We remember & act on others’ unique preferences, especially our kin and romantic partners; women are better at predicting some preferences (food, environments & pastimes) of their male partner than vice versa

Gifted at gift giving- An evolutionary perspective on preference accuracy. Diana Fleischman, Sophie Berryman. Human Behavior and Evolution Society 31st annual meeting. Boston 2019. http://tiny.cc/aa1w6y

Abstract: Humans remember and act on others’ unique preferences, especially our kin and romantic partners. Preference accuracy has been shown in two monogamous bird species, but there is little other comparative evidence. Although men give the majority of gifts cross-culturally, some evidence indicates women are better at anticipating the gift preferences of others, even when only presented with a photo of the recipient. Here I present a new study of 54 heterosexual romantic couples and their ability to predict one another’s preferences in domains including food, environments and pastimes. We find that, in two out of three domains, women are better at predicting the preferences of their male partner than vice versa. We also find that social intelligence, measured by accuracy in the "Mind in the Eyes" task, predicts better preference accuracy. We replicate a previous counterintuitive effect showing worse prediction accuracy in couples who have been together longer. We do not find that preference accuracy predicts relationship satisfaction. I’ll consider why we take the time, attention and effort to learn one another’s preferences from an evolutionary perspective.

Understanding hostility in online political discussions: Individuals who are hostile online are equally likely to be hostile offline, motivated by status and seeking to challenge existing political hierarchies

Why so angry? Understanding hostility in online political discussions. Alexander Bor, Michael Bang Petersen. Behavior and Evolution Society 31st annual meeting. Boston 2019. http://tiny.cc/aa1w6y

Abstract: Across Western democracies, online discussions about politics are considered uncivil, aggressive and hostile. Previous evolutionary research has explained this online political hostility as the result of the evolutionarily novel psychophysics of online environments: Lack of face-to-face interaction etc. down-regulate empathy and prompt hostility as a result of lack of emotion-regulation. On this explanation, online political hostility thus reflects an evolutionary mismatch. In contrast, we integrate (i) classical work on the adaptive functions of aggression and (ii) recent evidence on social media behavior to propose that online political hostility is deliberately employed as an instrumental strategy to further particular political agendas. We investigate this using a large representative sample of US citizens (N = 1500). Against the mismatch account, we find that individuals who are hostile online are equally likely to be hostile offline. Consistent with adaptive accounts of aggression, these individuals are motivated by status and seek to challenge existing political hierarchies. To this end, they invest more in online (vs. offline) political discussions as these discussions offer greater benefits (e.g., more interactions and greater reach) at lower costs. Thus, the hostility of online political discussions reflects a strategic investment in online discussions by aggressive prone individuals rather than an evolutionary mismatch.

Why do (some) women wear chokers? Wearing chokers is a function of short-term mating orientation and both male and female observers see them as such

Why do (some) women wear chokers? Laith Al-Shawaf, Heather Williquette. Human Behavior and Evolution Society 31st annual meeting. Boston 2019. http://tiny.cc/aa1w6y

Abstract: In a series of three studies, we generated and tested seven distinct hypotheses about why women wear choker necklaces and what they signify. Study 1 (n=102) showed that interest in wearing chokers and frequency of wearing chokers were both predicted by women’s sociosexuality, a stable individual difference variable that indexes a person’s dispositional orientation toward short-term mating. Study 2 (n=104) showed that male observers correctly use women’s chokers as a cue to their sociosexuality. Study 3 (n=100) showed that female observers also correctly use women’s chokers as a cue to their short-term mating orientation. These studies find clear support for the hypothesis that wearing chokers is a function of short-term mating orientation and no evidence for the other six hypotheses. These findings suggest two key conclusions: a) choker necklaces appear to be valid cues of sociosexual orientation and b) both male and female observers use them as such.

Alone Together: Important gender imbalances exist in what partners do when together; men are much more likely to watch TV and enjoy leisure while women do domestic chores

Alone Together: Gender Inequalities in Couple Time. Giacomo Vagni. Social Indicators Research, Jun 1 2019. https://link.springer.com/article/10.1007/s11205-019-02135-7

Abstract: An important body of research has used time diaries to assess the transformation of gender relationships at home. However, little is known about how partners perceive time shared together. While the household division of labor still remains heavily gendered, it can be expected that what partners do, even when they are together, is also gendered. The aim of this paper is to address the question of the discrepancy (or mismatch) in couples’ reporting of time together as well as the potential discrepancy in the activities engaged in during shared time. Using the 2015 UK Time Use Survey, I show that there is no gender difference in how partners report being together; however, important gender imbalances exist in what partners do when together. In particular, I find that, when together with their partner, men are much more likely to watch TV and enjoy leisure while women do domestic chores. I conclude by discussing different concepts of time together and the usefulness of couple-level diary data for studying gender relationships at home.

Keywords: Time use Gender Families Dyadic data

Pornography & aggression, & sexual & relationship dissatisfaction: Studies reveal methodological bias in favor of findings for effects that disappear when better methodologies are employed

Fisher, W. (2019). 004 How Science Studies Pornography Impact and What Science Can, and Cannot, Tell Us. The Journal of Sexual Medicine, 16(6), S2. doi:10.1016/j.jsxm.2019.03.461

Introduction:Sexuality clinicians have been concerned about the impact of pornography on sexual behavior at least since Dr. Ivan Bloch’s declaration, in 1902, that “There is no sexual aberration, no perverse act, however frightful,that is not photographically represented today.” Historically, the US, Britain,and Canada have funded national commissions to investigate the presumed negative effects of pornography, and in very recent years, the US Republican party platform and the US states of Florida and Utah have declared that pornography represents a public health crisis. More recently still, the Canadian parliament launched an inquiry into the health effects of online pornography.

Objective:There is a widely accepted social, scientific, and clinical narrative to the effect that pornography is a pervasive cause of sexual aggression against women, relationship devaluation and deterioration, and cause of sexual dysfunction. This presentation provides an overview of four decades of scientific research on the effects of pornography with a view towards soberly assessing what science can, and cannot, tell us about the effects of pornography on sexual aggression, relationship breakdown, and sexual dysfunction.

Methods:The methodological approaches and findings of classic studies inthe areas of pornography and sexual aggression, pornography and sexual and relationship satisfaction, and pornography-induced sexual dysfunction are reviewed and critiqued.

Results:Careful methodological review of laboratory experimentation concerning pornography and aggression reveals staggering methodological bias in favor of findings for effects of pornography on sexual aggression that disappear when appropriate methodologies are employed. Similarly, findings for effects of pornography on sexual and relationship dissatisfaction appear tohave been exaggerated in close-ended research that focuses solely on assessing harms and are not replicated in open-ended participant-informed research approaches. Findings for pornography-induced sexual dysfunction are ambiguous and may be interpreted to mean that individuals are receiving access to idiosyncratically arousing content in pornography that is not otherwise available to them in setting in which their sexual function is suboptimal.

Conclusions:This overview of research calls attention to the need for scientific skepticism in evaluating widely shared but scientifically questionable conclusions concerning the supposed negative effects of pornography. Attention to methodological bias, failures to replicate, and recognition of conflicting findings suggest that the science does not support the conclusions with any degree of consistency. At the same time, we do see patients clinically who have significant problems with their or their partner’s use of pornography, and careful, clinically relevant science on the actual role of pornography in these presentations and effective treatment approaches that focus appropriately on causal factors remains to be accomplished.

Biological Bases of Beauty Revisited: The Effect of Symmetry, Averageness, and Sexual Dimorphism on Female Facial Attractiveness Seems Smaller Than We Thought

Jones, A.L.; Jaeger, B. Biological Bases of Beauty Revisited: The Effect of Symmetry, Averageness, and Sexual Dimorphism on Female Facial Attractiveness. Symmetry 2019, 11, 279. https://www.mdpi.com/2073-8994/11/2/279

Abstract: The factors influencing human female facial attractiveness—symmetry, averageness, and sexual dimorphism—have been extensively studied. However, recent studies, using improved methodologies, have called into question their evolutionary utility and links with life history. The current studies use a range of approaches to quantify how important these factors actually are in perceiving attractiveness, through the use of novel statistical analyses and by addressing methodological weaknesses in the literature. Study One examines how manipulations of symmetry, averageness, femininity, and masculinity affect attractiveness using a two-alternative forced choice task, finding that increased masculinity and also femininity decrease attractiveness, compared to unmanipulated faces. Symmetry and averageness yielded a small and large effect, respectively. Study Two utilises a naturalistic ratings paradigm, finding similar effects of averageness and masculinity as Study One but no effects of symmetry and femininity on attractiveness. Study Three applies geometric face measurements of the factors and a random forest machine learning algorithm to predict perceived attractiveness, finding that shape averageness, dimorphism, and skin texture symmetry are useful features capable of relatively accurate predictions, while shape symmetry is uninformative. However, the factors do not explain as much variance in attractiveness as the literature suggests. The implications for future research on attractiveness are discussed.

Keywords: faces; attractiveness; symmetry; machine learning; averageness; dimorphism

MSM: Relative to a full battery condition, participants were more likely to agree to a hookup in the lowest battery condition; those men also endorsed a greater propensity for sensation seeking

Smartphone Battery Levels and Sexual Decision-Making Among Men Who Have Sex with Men. Alex Lopes, Kaylee Skoda, Cory L. Pedersen. Sexuality & Culture, June 1 2019. https://link.springer.com/article/10.1007/s12119-019-09620-8

Abstract: Smartphone-dating and hook-up apps are undeniable factors in the modern landscape of sexuality. In particular, gay and bisexual men have bridged social and societal barriers for connection by using these apps. Despite advantages afforded by such technological advancements, when individuals are faced with a low phone battery, a sense of urgency may be experienced, which can increase risk-taking behaviours to accommodate an impending phone “death”. The purpose of this study was to determine whether a draining smartphone battery would facilitate a greater likelihood of agreeing to a hookup encounter. Participants were randomly assigned to one of three battery life condition groups (5%, 20%, 100%) and were asked how likely they were to agree to a hookup with a simulated potential sexual partner. We discovered that, relative to a full battery condition, participants were more likely to agree to a hookup in the lowest battery condition. Additionally, men who reported a greater likelihood of agreeing to a hookup also endorsed a greater propensity for sensation seeking, regardless of the battery condition. These findings have practical implications for educating smartphone users who utilize dating and hookup apps about how scarcity decision-making and sensation-seeking can impact the ability to practice safe sexual behaviours.

Keywords: Hookups Dating applications MSM Decision-making Smartphones

There are studies in humans and animals revealing that lack of adequate sleep may facilitate sexual arousal, including objectively measured erections

Costa, R. M. (2019). Sleep and Sexual Arousal: A Complex Relation. The Journal of Sexual Medicine, 16(6), 946. doi:10.1016/j.jsxm.2019.03.267

I congratulate Smith and colleagues for their study on the relations of sexual function and sleep quality in older people,1a topic that deserves great attention. Their findings in a large representative English sample are extremely interesting, but also intriguing. Compared with men with high sleep quality, men with moderate sleep quality had greater odds of having erectile difficulties, but men with low sleep quality did not. Moreover, compared with men who sleep 6e8hours, men who sleep>8 hours had greater odds of having difficulties attaining orgasm, but men who sleep<6 hours did not.1Ifwe think that longer and better sleep favors sexual function, as many studies suggest, these are intriguing findings. Smith and colleagues note that the “results indicate that the relationship between sleep problems and sexual dysfunction is not as simplistic as previously suggested (poorer qualitysleep = greater dysfunction)” (p. 431), especially when several confounds are controlled.1

In this letter, I call the attention to an often overlooked phenomenon in the research on the relations between sleep and sexual function. There are studies in humans and animals revealing that lack of adequate sleep may facilitate sexual arousal, including objectively measured erections. After sleep deprivation, men diagnosed with psychogenic erectile dysfunction improved their erections in response to erotica,2 and for both sexes, poorer subjective sleep quality over the past month correlated with self-reports of greater unstimulated sexual arousal, that is, arousal in the absence of external stimuli.3 This occurred especially among those with higher testosterone levels.3 Among men, awakenings during both rapid eye movement (REM) and non-REM sleep increased visual attention to pictures of women, as assessed by eye-tracker, but the non-REM sleep awakening also disturbed REM sleep,4 which makes likely that it is the specific inhibition of REM sleep that has enhancing effects on sexual arousal. This is confirmed by research showing that REM sleep deprivation stimulates spontaneous erections and ejaculations in rats.5 The potential of REM sleep deprivation for increasing sexual arousal might be due to increased dopaminergic transmission, and it may also occur in women.3 Shortage of REM sleep is a likely consequence of many sleep disturbances.

Plausibly, in many cases, this effect may be offset by tiredness, difficulties interacting with the partner, psychopathology that develops due to lack of appropriate sleep, and perhaps by lower testosterone levels,3 among other factors. However, its presence might account for the complexity of the relationship between sleep and sexual function, as noted by Smith and colleagues.1

The False Enforcement of Unpopular Norms: The authors argue that people enforce unpopular norms to show that they have complied out of genuine conviction and not because of social pressure

The False Enforcement of Unpopular Norms. Robb Willer, Ko Kuwabara, Michael W. Macy. AJS Volume 115 Number 2 (September 2009): 451–90. https://pdfs.semanticscholar.org/1293/ecb55a2c5194fd1c16532c2c92599c6931fb.pdf

Abstract: Prevailing theory assumes that people enforce norms in order to pressure others to act in ways that they approve. Yet there are numerous examples of “unpopular norms” in which people compel each other to do things that they privately disapprove. While peer sanctioning suggests a ready explanation for why people conform to unpopular norms, it is harder to understand why they would enforce a norm they privately oppose. The authors argue that people enforce unpopular norms to show that they have complied out of genuine conviction and not because of social pressure. They use laboratory experiments to demonstrate this “false enforcement” in the context of a wine tasting and an academic text evaluation. Both studies find that participants who conformed to a norm due to social pressure then falsely enforced the norm by publicly criticizing a lone deviant. A third study shows that enforcement of a norm effectively signals the enforcer’s genuine support for the norm. These results demonstrate the potential for a vicious cycle in which perceived pressures to conform to and falsely enforce an unpopular norm reinforce one another.

The adaptive problems humans faced with respect to plants have left their mark on the human mind

How Plants Shape the Mind. Annie E. Wertz. Trends in Cognitive Sciences, June 1 2019, https://doi.org/10.1016/j.tics.2019.04.009

Abstract: Plants are easy to overlook in modern environments, but were a fundamental part of human life over evolutionary time. Recent work with infants suggests that the adaptive problems humans faced with respect to plants have left their mark on the human mind.

‘Everybody’s doing it’: on the persistence of bad social norms

‘Everybody’s doing it’: on the persistence of bad social norms. David Smerdon, Theo Offerman, Uri Gneezy. Experimental Economics, May 31 2019, https://link.springer.com/article/10.1007/s10683-019-09616-z

Abstract: We investigate how information about the preferences of others affects the persistence of ‘bad’ social norms. One view is that bad norms thrive even when people are informed of the preferences of others, since the bad norm is an equilibrium of a coordination game. The other view is based on pluralistic ignorance, in which uncertainty about others’ preferences is crucial. In an experiment, we find clear support for the pluralistic ignorance perspective. In addition, the strength of social interactions is important for a bad norm to persist. These findings help in understanding the causes of such bad norms, and in designing interventions to change them.

Keywords: Social norms Pluralistic ignorance Social interactions Equilibrium selection Conformity